The drunk personal assistant of former X Factor judge Tulisa Constostavlos told an undercover reporter that Simon Cowell was gay and he would make a move on him, a court has heard.

Contostavlos is on trial after allegedly boasting that she could "sort out" cocaine for 'Fake Sheikh' Mazher Mahmood and put the reporter in touch with her rapper friend Mike GLC who supplied the Class A drug.

Mr Mahmood yesterday denied "manipulating" the 26-year-old after he told her she was being considered for a leading role in a Slumdog Millionaire-type film tipped for Oscar glory alongside possible co-star Leonardo Di Caprio.

Appearing behind a screen at Southwark Crown Court, Mr Mahmood said he used "subterfuge" when he secretly recorded meetings with the ex-N-Dubz star as he attempted to establish whether she was involved in drugs.

The court has heard that Contostavlos spoke about being able to get "white sweets" and "green sweets" – allegedly code for cocaine and cannabis – while at London's Metropolitan Hotel with Mr Mahmood on May 10 last year.

Mr Mahmood said he also discussed Contostavlos's fee for the film with her PA Gareth Varey there. He said the singer would want £3million for the movie, the witness said.

Contostavlos put her hand over her mouth as a video was played of the men returning to Mr Mahmood's hotel suite after 2am. In the video recorded in Mr Mahmood's Metropolitan suite, he was heard asking Mr Varey, described as "visibly drunk" by Mr Mahmood, if Mr Cowell was gay.